Intraplanar heterostructure-mediated activation of peroxydisulfate for singular-electron-transfer degradation of organic pollutants

Abstract

Activating peroxydisulfate (PDS) through electron transfer pathways (ETP) is promising for degrading organic pollutants in aquatic environments. However, enhancing the activation selectivity remains a challenge. Herein, this study developed an intraplanar heterojunction with C-ring grafted g-C3N4 (CCN) as the catalyst, enabling PDS activation through a singular ETP. The CCN/PDS system achieved complete degradation and efficient mineralization (87.15 %) of bisphenol F (BPF), significantly reducing its ecological toxicity. Both experimental and theoretical investigations revealed that the intraplanar heterojunction could modulate the orbital occupation in g-C3N4/PDS, enhancing PDS adsorption and activation selectivity. Driven by the differences in the frontier orbital energy, the CCN/PDS system achieved a singular ETP without active species formation. The CCN/PDS system efficiently degraded BPF in complex water environments, showing performance stability across a wide pH range and against various coexisting ions. In a continuous-flow automatic catalytic device, the CCN/PDS system maintained a constant 100 % BPF degradation for 600 min. This study advances the understanding of PDS activation via singular ETP and introduces a new approach to water purification.